The present invention relates to an apparatus for crimping cables, particularly cables made of synthetic plastic filaments. Even more particularly, this invention relates to a crimping apparatus provided with a compression chamber.
Crimping of cables formed of synthetic plastic filaments in mechanical compression chambers takes place in practice at the present time at operation speeds up to 300 m/min. A number of filament bundles are pulled out from a container and are combined into a cable which is fed with an overall size of up to 4,000,000 dtex into the compression chamber. The operation of the apparatus is carried out in such a fashion that the starting end of the cable is inserted into the gap between the pressing rolls when the apparatus is non-operative, and then the speed of the movable components of the apparatus is increased.
Such methods of crimping cables have been already described. In conventional methods, however due to the intermediate storage of the cable in the containers there have been losses. With these methods, the newly spun synthetic filaments are stretched in a continuous process, then crimped and eventually cut off to a size suitable for staple. It must be natural to assume that the insertion of the cable into the compression chamber should be carried out at a full operational speed. With customary dry spinning methods, the spinning speed is 500 m/min or higher so that, with a stretching ratio from 1 to 4 for the stretched cable, the speed of at least 2,000 m/min results. However, it has been very difficult or practically impossible with conventional mechanical compression chambers to insert the cable into such a chamber with the above speed.
German Pat. No. 1,816,028 discloses a crimping apparatus with a compression chamber in which one of the pressing rolls together with the pivotally positioned intermediate element, which closes the chamber in the operative position, is supported on rocking arm so that the pressing roll is pivoted out from the operation position. Thereby the cleaning and maintenance of the compression chamber are facilitated. The publication, however does not suggest that a cable could be inserted into the open compression chamber while the motors of the device are switched on. Obviously the insertion of the cable during the operation of the motors into the open compression chamber is not possible in the disclosed device because lateral access to the chamber is blocked by the machine components.
German Offenlegungsschrift No. 1,435,365 discloses an apparatus in which the compression chamber is formed by two suspended compression rolls and in which a gap between the rolls can be freed at one side by returning flaps provided on the side plate. However, there is no suggestion that the compression rolls could be moved away from the operative position to provide an enlarged gap between the rolls.
A crimping device for crimping synthetic plastic filaments has been also disclosed, for example, in applicant's U.S. Pat. No. 3,887,972.